Why does Gwibber show a security warning when I try to authenticate my Facebook account?

http://askubuntu.com –
When I try to Authorize in the end, it shows:
Success
SECURITY WARNING: The above URL is NOT NOT VALID FOR A CASH
CARD OR GIFT CARD. Giving away the URL may result in your account
being HIJACKED.
and Gwibber doesn't connect to Facebook.
(HowTos)